package com.atguigu.gmall.realtime.util;

import java.util.concurrent.LinkedBlockingDeque;
import java.util.concurrent.ThreadPoolExecutor;
import java.util.concurrent.TimeUnit;

/**
 * @author Felix
 * @date 2022/8/28
 * 线程池工具类
 * 双重校验锁解决单例设计模式懒汉式 线程安全问题
 */
public class ThreadPoolUtil {
    private static volatile ThreadPoolExecutor threadPoolExecutor;

    public static ThreadPoolExecutor getInstance(){
        if(threadPoolExecutor == null){
            synchronized(ThreadPoolUtil.class){
                if(threadPoolExecutor == null){
                    System.out.println("~~~开辟线程池~~~");
                    threadPoolExecutor
                        = new ThreadPoolExecutor(4,20,300, TimeUnit.SECONDS,new LinkedBlockingDeque<Runnable>(Integer.MAX_VALUE));
                }
            }
        }
        return threadPoolExecutor;
    }
}
